Car-brake



(No Model.)

. W. T, BOTHWELL.

GAR BRAKE.

' No. 444,145. Patented Jan. 6,1891.

NITED STATES Arnw'r rrron.

WILLIAM T. BOTHWELL, OF JERSEY CITY, NEIV JERSEY, ASSIGNOR OF ONE- HALF TO ALFRED R. BOLUSS, OF NORWVOOD, OHIO.

C A R B RA K E SPECIFICATION forming part of Letters Patent No. 444,145, dated January 6, 1891.

Application filed April 18, 1890- Serial No. S l8,5l4. (No model.)

To all whom it may concern..-

Be it known that I, WILLIAMT. Bo'rHwELL, a citizen of the United States, residing at J ersey City, in the State of New Jersey, have invented certain new and useful Improvements in Oar-Brakes; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention has relation to an improven1 ent in car-brakes, and is particularly adapted for use in that class of brakes known as fluid-pressure brakes.

The invention will be fully understood from the following description and claims, when taken in connection with the accompanying drawings, in which Figure 1 is an inverted plan view of my improved device, showing the application of the same to a brake-bar and the brake-chains in position. Fig. 2 is a vertical longitudinal sectional view taken in the plane indicated by the dotted lines 3 g on Fig. 1, with the piston drawn in. Fig. 3 is a cross-sectional view taken in the plane indicated by the dotted line or a: on Fig. 1. Fig. 4 is an end view with the stem of the piston in section. Fig. 5 is a perspective view of the annulus removed from the brake-cylinder.

Referring by letter to the said drawings, A indicates a brake-bar, B a brake-rod, and O a brake-lever, which may be of any ordinary or approved construction.

D indicates a brakecylinder having an induction-pipe a at one end, which is designed to communicate with the fluid-pressure linepipe, or the pipe leading from a storage-cylinder, as the case may be. This brake-cylinder is secured beneath a car in a proper position with respect to the brake mechanism, and preferably between the trucks of a car, by means of screws or other suitable fastening devices, which pass through a flange 1), formed on or secured to the upperlongitudinal side of the cylinder. Arranged within this cylinder, and at one end thereof, is an annulus 0, provided at suitable points with recesses d, designed to seat anti-friction rollers or balls 6. This ring or annulus may be secured in the cylinder by screws or the like, so that it may be removed when desired, although in some cases the ring may be dispensed with, as it is only necessary that rollers or balls be interposed between the inner wall of the cylin- 5 5 der and the superficial area of the piston to engage guides or grooves, as will be presently explained, whereby a partial rotation may be imparted to the piston in its reciprocatory movement.

E indicates the piston, which is arranged within the cylinder and has a suitable head f for the impact of the steam or fluid pressure. This piston is provided lengthwise with a series of spiral grooves or channel g, there bein g preferably three of such grooves employed, and the balls or rollers e are designed to partly enter said grooves or engage the Walls thereof.

The piston is provided at its outer end with a plate h, designed to cover the outer ends of the spiral grooves or channels, and this plate is provided at diametrically-opposite points with short arms or branches 1', carrying pins or studs is for the attachment of one end of the brake-chain F.

It is obvious that in some cases the short arms may be dispensed with and the attachment of the brake-chains made directly to the outer end of the piston at opposite eccentric points. The piston is also provided with a stem G, extending horizontally from its outer end, and this stem passes through a guideeye in a depending arm or guide H.

In operation it will be seen that as air or pressure is let into the pipe a from the linepipe or reservoir its action upon the head f of the piston will force the latter outwardly, and through the medium of the anti-friction rollers or balls and the spiral grooves said piston will be given a partial rotation in its 0 reciprocating movement. This will cause the brake-chains F to move in opposite directions in a semicircular manner and draw upon one end of the brake-levers C, while the brakerods 1) will serve to manipulate the brake- 5 bars A, and consequently the shoes at the wheels of the truck. \Vhen pressure is released at the pipe 0;, and consequently its force reduced upon the head of the piston, the piston is allowed to reverse its motion and releasethe [O0 brake from the wheels of the truck. IVhile I have shown in Fig. l of the drawings the brake-levers O horizontally disposed, yet in practice these levers assume a vertical position. I have shown them horizontally for the purpose of better illustrating the invention.

Having described my invention, what I claim is l. The combination, with a brake-cylinder, of a partially-rotatable piston adapted to be connected with brake mechanism, and antifriction guide-rollers interposed between the cylinderand the piston, substantially as specified.

2. The combination, with a piston having spiral grooves arranged lengthwise thereof, of a cylinder and rollers to engage said grooves, substantially as specified.

3. The combination, with a brake-cylinder carrying rollers, of a piston arranged in the cylinder and having longitudinally-arranged spiral grooves to receive the rollers, substantially as specified.

4. The combination, with a brake-cylinder, of a ring or annulus arranged in one end and adapted to receive the piston-stem, and the balls arranged in the ring and the piston having lengthwise spiral grooves to receive the balls, substantially as specified.

5. A piston having longitudinally-arranged spiral grooves and diametrically arranged arms at one end for the attachment of brakechains, in combination with a cylinder and rollers whereby the piston is rolled or given a partial rotation in its reciprocating movements, substantially as specified.

6. A car-brake mechanism having a partially-rotatable reciprocating piston provided at its outer end and eccentrically thereon with suitable means for the attachment of brakechain, in combination with a brake-cylinder, substantially as specified.

In testimony whereof I aiiix my signature in presence of two witnesses.

VILLIAM T. BOTHWELL.

Witnesses:

C. H. RAEDER, THOS. E. TURPIN. 

